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Removing the delayed interrupt mechanism, research is not complete enough for implementation

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This commit is contained in:
Lior Halphon 2017-09-08 12:58:35 +03:00
parent 72d26c7046
commit 0f643e01b7
4 changed files with 2 additions and 15 deletions
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11
Core/display.c
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@ -300,7 +300,6 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
uint8_t vram_blocking_rush = gb->is_cgb? 0 : 4;
for (; cycles; cycles -= atomic_increase) {
gb->delayed_interrupts &= ~3;
gb->display_cycles += atomic_increase;
/* The very first line is 4 clocks shorter when the LCD turns on. Verified on SGB2, CGB in CGB mode and
CGB in double speed mode. */
@ -344,10 +343,6 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 1;
gb->io_registers[GB_IO_IF] |= 1;
if (gb->is_cgb) {
/* See comment on STAT interrupt at the end of the loop */
gb->delayed_interrupts |= 1;
}
/* Entering VBlank state triggers the OAM interrupt. In CGB, it happens 4 cycles earlier */
if (gb->io_registers[GB_IO_STAT] & 0x20 && !gb->is_cgb) {
@ -563,12 +558,6 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
if (gb->stat_interrupt_line && !previous_stat_interrupt_line) {
gb->io_registers[GB_IO_IF] |= 2;
if (gb->is_cgb) {
/* On CGB, the STAT interrupt is not aligned to a T-Cycle, therefore it is only effective the next T-Cycle
Todo: verify on DMG mode CGB. This was only tested on LYC STAT interrupts, should be tested on others
as well. */
gb->delayed_interrupts |= 2;
}
}
#if 0

1
Core/gb.h
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@ -332,7 +332,6 @@ struct GB_gameboy_internal_s {
GB_PADDING(uint16_t, serial_cycles);
uint16_t serial_cycles; /* This field changed its meaning in v0.10 */
uint16_t serial_length;
uint8_t delayed_interrupts; /* When an interrupt occurs while not aligned to a T-cycle, it must be "delayed" */
bool dont_delay_timer_interrupt; /* If the timer glitch causes a TIMA overflow, it causes the timer to overflow
with different timing, so the triggered interrupt is not delayed.
Todo: needs test ROM. */

3
Core/timing.c
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@ -82,14 +82,13 @@ static void GB_ir_run(GB_gameboy_t *gb)
static void advance_tima_state_machine(GB_gameboy_t *gb)
{
gb->delayed_interrupts &= ~4;
if (gb->tima_reload_state == GB_TIMA_RELOADED) {
gb->tima_reload_state = GB_TIMA_RUNNING;
}
else if (gb->tima_reload_state == GB_TIMA_RELOADING) {
gb->io_registers[GB_IO_IF] |= 4;
if (!gb->dont_delay_timer_interrupt) {
gb->delayed_interrupts |= 4; // Timer interrupt is not aligned to a T-cycle and therefore is effective only the next one.
// Todo
}
gb->tima_reload_state = GB_TIMA_RELOADED;
}

2
Core/z80_cpu.c
View File

@ -1337,7 +1337,7 @@ static GB_opcode_t *opcodes[256] = {
void GB_cpu_run(GB_gameboy_t *gb)
{
gb->vblank_just_occured = false;
uint8_t interrupt_queue = gb->interrupt_enable & gb->io_registers[GB_IO_IF] & 0x1F & ~gb->delayed_interrupts;
uint8_t interrupt_queue = gb->interrupt_enable & gb->io_registers[GB_IO_IF] & 0x1F;
if (interrupt_queue) {
gb->halted = false;